In this article, the author examines the links between high stakes testing policies, school organization processes, and instructional practice using data from a study of K-5 and K-8 schools in Chicago. He argues that although the policy environment penetrates the classroom, this penetration is partial--stronger on some aspects of instruction than others--and its impact unpredictable. He highlights four organizational patterns in the schools he studied that have implications for the link between accountability policy and instruction. These patterns include the stronger influence of accountability policy on content as opposed to pedagogy, the centrality of teaching colleagues in teachers' advice-seeking networks, the predominance of didactic as opposed to interactive forms of instruction, and the differential responses to accountability policy and unequal distribution of resources across schools. After outlining these patterns, he discusses their implications for understanding the links between accountability policy, instruction, and educational equity. (Contains 1 table, 3 figures and 13 notes.)